Research On Diverse And Realistic 3D Sunken Relief Generation Based On A Single Image

Relief is a kind of three-dimensional(3D)modeling art that combines painting and sculpture art which can present and display more information in less space.Relief can be divided into three forms: high relief,bas relief and sunken relief.Among them,the sunken relief is a relief form obtained by carving out corresponding redundant materials from the background plane according to the pattern.Therefore,compared with the other two relief forms,sunken relief takes up the least space.Hollow-out relief is a form of sunken relief which is obtained by carving out the background based on the sunken relief.In recent years,with the rapid development of computer graphics and 3D modeling technology,there have been great progress in the area of 3D digital relief generation.The digital relief sculpture generated by computer-aided modeling techniques is easy to be saved and modified,and overcomes the drawback of low production efficiency of traditional manual relief production which is hard to modify the product.This paper focuses on generating various and realistic sunken relief from a single image and mainly completes the following work:(1)Sunken relief generation from image based on feature enhancementWith the existing problems of complicated algorithm and low efficiency of the 3D model based sunken relief generation method,a 3D digital sunken relief generation method based on image feature enhancement is proposed in this paper.The method first extracts the feature lines from the image through threshold detection method,and then uses feature enhancement techniques,such as USM and local information enhancement,to enhance the image features and obtain a more smooth and clear relief image.Finally,the mesh triangulation operation is applied to construct the 3D sunken relief model.The experimental results show that this method is simple and effective compared with the method of generating sunken relief from 3D model.The average time of per thousand faces is 0.253 seconds.However,the sunken relief generated by this method lacks diversity and sense of design,and the surface of the relief does not have the height change of the real sunken relief.(2)Fractal-based sunken relief input image generation methodIn order to solve the problem of lacking diversity and creativity in the generated sunken relief model,this paper proposes a pattern generation method based on fractal rules,which enhances the diversity of resulting relief model by generating various of images.Fractal images have high artistic and aesthetic appearance,and various types of images can be generated by different rules.Thus,the diversity of sunken relief could be enriched consequently.In this paper,classical fractal patterns are generated first.Then,fractal images with smooth lines are generated by using Bezier curve.And more complex and beautiful fractal patterns are collaged by using the fractal iteration rules on the basis of existing simple art images.And all these fractal images are used as input images to generate sunken relief.(3)Sunken relief generation from fractal image based on distance transformationIn order to solve the problem that the generated sunken relief surface is flat and lacks of the height change of the real sunken relief,a sunken relief generation method based on distance transformation is proposed.Taking a fractal image as input,this paper first distinguishes the foreground and background by image binarization.And then the distance transformation is used to obtain the height change of the surface.After that,the height is compressed to a certain range which is more in the line with the real height of the sunken relief by gray level transformation.Results show this method is effective to generate sunken relief with greater diversity and more real height.After obtaining the sunken relief,we also generate hollow-out relief by deleting the triangular meshes of the background.